JPH0782690A - Production of raw paper for casing - Google Patents

Abstract

PURPOSE:To provide a method for producing raw paper for casing, having high wet strength and alkali resistance as well as excellent impregnation characteristics and used for casing for packing a meat product such as ham or sausage. CONSTITUTION:A sheet-like substrate using cellulose pulp as a raw material is treated with a mixed aqueous solution consisting of 0.05-3.0wt.% of chitosan or a chitosan salt, 0.05-3.0wt.% of water-proofing agent and 0.2-2.0wt.% of polyvinyl alcohol (PVA) and being <=70 cps in viscosity of solution measured by type B viscometer by impregnation, coating, etc., an the treated substrate is dried so that contents of chitosan, the water-proofing agent and PVA based on absolutely dried paper substrate are 0.09-6.0wt.%, 0.09-6.0wt.% and 0.3-4.0wt.%, respectively. Since the resultant casing is free from unevenness of impregnation of viscose and has uniform strength, the casing is excellent in quality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a base paper for casing. More specifically, the present invention relates to a method for producing a base paper for a casing used for a casing for filling meat products such as ham and sausage having good wet strength and alkali resistance and excellent impregnation characteristics.

[0002]

2. Description of the Related Art Processed meat products such as ham and sausages are manufactured by filling a tube-shaped casing with a kneaded product prepared by mixing raw materials and then subjecting it to heat treatment, sterilization treatment, smoke treatment and the like. There are natural casings and artificial casings (cellulose casings, collagen casings, plastic casings, fibrous casings, etc.), and artificial casings are cheaper and more hygienic than natural casings, and their product size is constant. Widely used due to its advantages.

However, the cellulose casing has the drawbacks of low strength and weakness to humidity, and the plastic casing cannot be smoked. Therefore, large-sized loin ham and press ham have hitherto been used. A strong fibrous casing that can smoke is used for this purpose.

The fibrous casing is a paper base material made of cellulose pulp impregnated with viscose, coagulated,
It has been regenerated, and this method is described in US Pat.
No. 105,273. Viscose is an aqueous solution containing 7% by weight of cellulose and 6% of sodium hydroxide, and therefore the paper base material is required to have wet strength and alkali resistance (strong resistance to alkaline liquid). In order to impart wet strength and alkali resistance that can withstand the above-mentioned viscose impregnation to such a paper substrate, US Pat.
As disclosed in Nos. 35,613 and 3,275,456, pre-impregnation and regeneration treatment of a dilute viscose liquid (cellulose content of about 1%) are performed.

In Japanese Patent Publication No. 4-16129, a paper base material composed of cellulose pulp such as hemp pulp and wood pulp is used together with pulp or paper,
It is disclosed that chitosan or a chitosan salt is added and applied or treated by immersing it in the above aqueous solution after forming a paper base material such as a non-woven fabric. However, only by treating the pulp or paper base material with chitosan or chitosan salt alone, the wet strength is relatively high, but the alkali resistance is low and the strength is still insufficient.

On the other hand, a method of increasing paper strength by adding chitosan salt and polyamide epichlorohydrin resin together to a pulp slurry is disclosed in Japanese Patent Laid-Open No. 335008/53. The strength of the paper made is not yet practically sufficient.

Further, in order to impart high wet strength and alkali resistance using chitosan, it is necessary to hold the chitosan in a high ratio in the pulp fiber constituting the paper base paper. The external addition method of dipping or applying the above-mentioned chemicals on the paper base is more efficient than the internal addition method of adding and making paper. However, in the case of the external addition method, since a high chemical content must be obtained, it is necessary to use a highly concentrated chitosan-dissolved aqueous solution, but the chitosan-dissolved aqueous solution can be measured by a B-type viscometer. Has a relatively high viscosity and is 100c
A high-concentration chitosan-dissolved aqueous solution having a viscosity exceeding ps is difficult to handle in the actual operation during the impregnation or coating, and uneven impregnation occurs, resulting in variations in the obtained quality, which is disadvantageous.

The present inventors have diligently studied such a problem,
A method for producing a fibrous casing base paper in which a sheet-like base material made of cellulose pulp is treated with an aqueous solution in which chitosan or a chitosan salt and a water-proofing agent are mixed has been proposed (Japanese Patent Application No. 5-101397). According to this method, the viscosity of the chitosan-dissolved aqueous solution for impregnation can be suppressed to 100 cps or less (B-type viscometer), the operation becomes relatively easy, and the variation in the obtained quality can be relatively reduced. However, in order to maintain high wet strength and alkali resistance at a high level, it is necessary to use relatively high values for the content of chitosan and the content of waterproofing agent per paper base material after impregnation. No viscosity was obtained, and the viscosity of the chitosan-dissolved aqueous solution was 100 cps or less, but could not be so low.

By using a water-proofing agent in combination with chitosan as described above, the wet strength, alkali resistance and impregnation unevenness of the paper substrate could be considerably improved, but the occurrence of unevenness in the pre-impregnation with the mixed solution was finally When impregnated unevenness due to viscose is generated, and a casing manufactured using such casing base paper is filled with meat products such as ham and sausage, the uniformity of the diameter of the filled one is significantly impaired,
It is one of the criteria for determining the quality of a product. Therefore, the appearance of an impregnation method that further reduces the viscosity of the chitosan-dissolved aqueous solution, facilitates the adjustment during impregnation, has no impregnation unevenness, and can achieve equivalent strength quality even with a small chitosan content Is desired.

[0010]

In view of the above situation, the present inventors have used chitosan having less wet strength and alkali resistance of a base paper for a casing using a sheet-like base material composed of cellulose pulp as a raw material. As a result of earnestly researching a method for improving the same, a polyvinyl alcohol resin (hereinafter referred to as PVA) is further used in combination with chitosan or a mixed solution of a chitosan salt and a water-proofing agent, and the sheet-shaped substrate is treated with this mixed aqueous solution. Then, the inventors have found that the drawbacks of the prior art can be solved with a lower solution viscosity and a lower chitosan content, and have completed the present invention.

The object of the present invention is to use a chitosan-dissolved aqueous solution having a lower solution viscosity, a smaller chitosan content, a higher wet strength, an extremely excellent resistance to an alkaline liquid, and an improved impregnation unevenness. It is intended to provide a method for manufacturing a base paper for a casing.

[0012]

DISCLOSURE OF THE INVENTION The present invention is for a casing characterized in that a sheet-like base material made of cellulose pulp is treated with an aqueous solution in which a chitosan or chitosan salt is mixed with a waterproofing agent and a polyvinyl alcohol resin. It is a method of manufacturing base paper.

The PVA used in the present invention may be any water-soluble PVA, and in addition to ordinary PVA, carboxyl group-modified PVA, sulfonic acid group-modified PVA,
Anion-modified PVA such as phosphoric acid group-modified PVA, cation-modified PVA, or modified PVA obtained by copolymerizing ethylene or vinyl ether, vinyl ester, (meth) acrylamide, alpha-olefin, etc. having a long-chain alkyl group.
And the like, which are appropriately selected and used.

The degree of polymerization of these PVAs is not particularly limited, but is usually selected from the range of 100 to 3000, and the degree of saponification is not particularly limited as long as PVA is water-soluble, but is usually 70 to 100 mol. Those in the range of% are preferably used.

The chitosan used in the present invention is a complex of chitin, calcium, protein, etc., which is usually contained in the shells of crustaceans such as crab and shrimp, treated with acid and alkali, and taken out as a chitin simple substance. It is obtained by treating this chitin with a strong alkali and then deacetylating it, and is generally used as a food additive. The chitosan salt is obtained by dissolving the chitosan in an inorganic acid or an organic acid.

Examples of the inorganic acid include hydrochloric acid, nitric acid, sulfuric acid,
Phosphoric acid, boric acid and the like can be mentioned, and as the organic acid, formic acid, acetic acid, glucose acid, oxalic acid, succinic acid,
Examples thereof include adipic acid, malic acid, maleic acid, fumaric acid, tartaric acid, phthalic acid, isophthalic acid, terephthalic acid and lactic acid. However, when used for fibrous casing, acetic acid, adipic acid, malic acid, fumaric acid, tartaric acid, lactic acid and the like, but when used for fibrous casing of the present invention acetic acid, adipic acid, apple Acids such as fumaric acid, tartaric acid and lactic acid, which are commonly used as food additives, are preferably used.

The chitosan salt is soluble in water, but since chitosan is poorly soluble in water, it is used by dissolving it in the organic acid. In this case, the amount of the organic acid used is 0.1% by weight of chitosan. To 1.2 times the amount, preferably 0.3 to 0.6 times the amount is appropriately selected and used. Dissolution of chitosan with an acid is preferably carried out at a temperature of 40 ° C. or lower, preferably at room temperature of 15 to 25 ° C. for 30 to 180 minutes while stirring to suppress self-reaction.

The chitosan used has an amino group of 40
%, Preferably 90% or more, or those in which some or all of these amino groups are converted to ammonium groups by an acid are used. As the molecular weight of chitosan, chitosan having a molecular weight of 500,000 or less, preferably in the range of 5 to 300,000 can be used.

On the other hand, examples of the water-proofing agent used together with chitosan include urea formaldehyde resin, melamine formaldehyde resin, glyoxal, dialdehyde starch, polyamide epichlorohydrin resin, polyethyleneimine and the like. Formalin-free polyamide epichlorohydrin resin is preferably used as the waterproofing agent.

The mixed aqueous solution of chitosan or chitosan salt used in the present invention, the water-proofing agent and PVA is prepared by first dissolving chitosan and PVA in water containing an organic acid or by dissolving chitosan or PVA in an aqueous solution containing PVA. It is prepared by adding a chitosan salt and an acid to dissolve it, and then adding a waterproofing agent, or by mixing an aqueous solution of PVA with a chitosan aqueous solution of an organic acid, and then adding a waterproofing agent. It

The compounding ratio of chitosan or chitosan salt, water-proofing agent and PVA is expressed in terms of solid content concentration in the mixed aqueous solution and used in the following range. That is, the content of chitosan or chitosan salt is 0.05 to 3.0% by weight, preferably 0.1 to 2.0% by weight, and if the concentration is less than 0.05% by weight, the strength is insufficiently expressed. If it exceeds 0.0% by weight, the viscosity of the impregnating liquid exceeds 70 cps, making it difficult to control the impregnating amount and to handle the impregnating liquid, so that it becomes difficult to operate and the cost increases. Water resistance agent is from 0.05 to
It is used in an amount of 3.0% by weight, preferably 0.1 to 2.0% by weight. If the concentration of the water resistant agent is less than 0.05% by weight, the effect of improving the development of strength is low. If it exceeds, the strength improving effect reaches saturation, which is not economical. PVA
Is 0.2 to 2.0% by weight, preferably 0.4 to 1.0
Used in wt%. When the solid content concentration of PVA is less than 0.2% by weight, the strength development is insufficient, and it is 2.0% by weight.
When it exceeds, the strength is saturated and the impregnation property of viscose is impaired, which is not suitable.

The method for treating the sheet-shaped substrate with the chitosan-dissolved aqueous solution is not particularly limited. For example, the sheet-shaped substrate is impregnated in the aqueous solution, or the aqueous solution is prepared by a size press, a roll coater, a brush coater or the like. However, other treatment methods can also be adopted. The content of chitosan in the sheet-like substrate treated in this way is 0.09-
6.0% by weight, preferably 0.2 to 4.0% by weight, the waterproofing agent is 0.09 to 6.0% by weight, preferably 0.2 to
4.0 wt% and PVA are adjusted to 0.3 to 4.0 wt%, preferably 0.7 to 2.0 wt% by changing the compounding ratio, impregnation amount or coating amount. The drying condition after the treatment is not particularly limited, but usually 90 to 150 ° C.
The method of using a warm air dryer is preferably used.

The sheet-like base material for the present invention includes, for example, non-wood fibers such as wood pulp such as bleached kraft pulp, hemp pulp (manila hemp, sisal hemp, flax, hemp, jute), kozo, mitsumata, etc. Pulp from (peel fiber) or the like, or pulp obtained by appropriately selecting and mixing these pulps, preferably hemp pulp as paper stock, obtained by paper making in a known wet paper machine is suitably used.

Pulp is not beaten (freeness 650 to 750 mlcs for producing a porous sheet-like substrate.
It is preferably used in f), but since the binding strength increases due to beating, the freeness is 500 m depending on the application.
Pulp reduced to lcsf may be used in whole or in part. Further, in order to impart more strength to the raw material, it is preferable to add a chemical such as a water resistant agent or a wet strength agent in advance for papermaking. The basis weight of the sheet-shaped substrate varies depending on the desired use, but is 15 to 3 for the base paper for casing.
It is appropriately selected and used in the range of 0 g / m ² .

[0025]

The present invention will be described in more detail with reference to the following examples, but of course the present invention is not limited thereto. In the examples and comparative examples,% means% by weight unless otherwise specified.

Example 1 Un-beaten (freeness 690 mlcsf) commercially available hemp pulp from Philippines (product number: S-2B) had a slurry concentration of 2.
Polyamide epichlorohydrin resin (WS-570, manufactured by Japan PMC) per weight of absolutely dry pulp at 5% was 1.5.
%, And sufficiently stirred to prepare a paper material, and a sheet-like base material having a basis weight of 23 g / m ² was prepared using a laboratory paper machine.

On the other hand, the degree of polymerization is 1800 and the degree of saponification is 98 to 9
9% PVA (N-300, manufactured by Nippon Synthetic Chemical Industry) aqueous solution and chitosan (EL, manufactured by Yaizu Suisan Chemical Co., Ltd.) aqueous solution (acetic acid: chitosan = 1: 1 (solid content weight ratio)) and water resistant Polyamide epichlorohydrin resin (WS-570, manufactured by Japan PMC) was mixed as an agent, and the solid content concentration in the aqueous solution after mixing was chitosan: 1.0%, polyamide epichlorohydrin resin: 0.6%, PVA:
It was adjusted to be 1.5%. The viscosity of the mixed aqueous solution for impregnation measured by a B-type viscometer is 20 cps (60 rp).
m, 20 ° C.).

The sheet-shaped substrate was treated by impregnating it with an aqueous solution for impregnation in which the chitosan, the water-proofing agent and PVA were mixed in an experimental impregnator and squeezing excess liquid using a rubber roll squeezing machine. After the removal, the impregnated sheet-shaped substrate was dried in a hot-air circulating dryer adjusted to a temperature of 105 ° C.

The content of chitosan in the obtained sheet-shaped substrate was 2.0%, the water-proofing agent was 1.2%, and the PVA was 3.0%, based on the absolutely dried paper substrate before treatment. . The wet tensile strength and alkali resistance of the obtained sheet-shaped substrate were measured by the following methods. Further, the impregnation unevenness was evaluated by the following method to evaluate its quality.

Test Method (1) Wet Tensile Strength: According to JIS P8135. (2) Alkali resistance: According to JIS P 8135, instead of water, add 1% to a 6% sodium hydroxide aqueous solution.
The tensile strength after soaking for 0 minutes was measured.

Evaluation Method of Impregnation Unevenness One sheet of the sheet-like base material as a base paper for casing obtained as described above was coated with 1000 g / m ^{2 of an} aqueous viscose solution having a cellulose content of 7%, and then 30
% Aqueous solution of ammonium sulfate for 20 minutes, further immersed in 5% aqueous solution of sulfuric acid for 20 minutes, then washed,
A casing having a basis weight of 93 g / m ² was prepared by drying, and the transparency of the obtained casing was visually observed to find that the transparency was uniform and good. Yes, the non-uniform ones were marked as unacceptable and indicated by x.

Example 2 The solid content concentrations of chitosan, water-proofing agent (polyamide epichlorohydrin resin) and PVA in the impregnating aqueous solution were 2.0%, 0.6% and 1.2%, respectively. Viscosity measured by viscometer is 50 cps (60 rpm, 20
(° C)) except that the sheet-like substrate was impregnated with the aqueous solution in the same manner as in Example 1 to prepare an impregnated sheet-like substrate. The contents of chitosan, waterproofing agent and PVA in the sheet-shaped substrate thus obtained were 4.0%, 0.6% and 2.3%, respectively. The strength and alkali resistance were measured, and the transparency of the casing obtained by treating with an aqueous viscose solution was evaluated.

Comparative Example 1 The chemical components in the impregnating aqueous solution consisted of chitosan and a water-proofing agent (polyamide epichlorohydrin resin), and the solid concentration of each was 3.2% and 0.6% (the B-type viscometer of the aqueous solution). Viscosity of 100 cps (60 rpm, 20
C.)) was used to impregnate the aqueous solution with the sheet-shaped substrate to prepare an impregnated sheet-shaped substrate. The contents of the chitosan and the water-proofing agent in the sheet-like base material thus obtained were 6.3% and 1.2%, respectively.
The wet tensile strength and the alkali resistance were measured in the same manner as in Example 1, and the transparency of the casing obtained by treating with the aqueous viscose solution was evaluated.

Table 1 shows the measurement results of the aqueous solutions for impregnation and the sheet-shaped substrates obtained in Examples 1 to Comparative Example 1 and the evaluation results of the casing.

[0035]

[Table 1]

As can be seen from Table 1, a sheet-like substrate composed of cellulose pulp is composed of chitosan or chitosan salt, a water-proofing agent and PVA, and the viscosity of the aqueous solution is 10
By the impregnation treatment with the mixed aqueous solution for impregnation significantly lower than 0 cps, the treated sheet-shaped substrate obtained has high wet tensile strength and excellent alkali resistance, and is evenly and uniformly impregnated with the viscose aqueous solution. And has desirable characteristics as a casing (Examples 1 and 2). However, when PVA is not used, although the wet strength and alkali resistance are remarkably excellent, the viscosity of the aqueous solution is not low, so that the aqueous solution for impregnation containing chitosan is not uniformly impregnated, and in proportion thereto, viscose. Since the impregnating property of the aqueous solution is also non-uniform, the impregnated portion and the non-impregnated portion are randomly generated in the obtained casing,
Eventually, the strength of the casing becomes uneven, and when the meat such as ham and sausage is packed, it causes a serious defect that the diameter of the product is not constant, which is not practical (Comparative Example 1).

[0037]

As described in detail above, the present invention can impart high wet strength and excellent alkali resistance to a sheet-like base material composed of cellulose pulp, so that it does not break or break during the viscose impregnation step. It is possible to provide a method for producing a base paper for a casing for a casing having uniform quality, which does not cause operational troubles and can maintain the solution viscosity of the pre-impregnation liquid at an extremely low level so that excellent impregnation characteristics can be obtained. Play.

Claims (1)

[Claims] 1. A method for producing a base paper for a casing, which comprises treating a sheet-like base material made of cellulose pulp with an aqueous solution in which chitosan or a chitosan salt is mixed with a waterproofing agent and a polyvinyl alcohol-based resin.